package models;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.Lob;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;

import play.db.jpa.Model;

@Entity
public class Post extends Model {
    public String title;
    public Date   postedAt;

    @Lob
    public String content;

    @ManyToOne
    public User   author;
    
    
    @ManyToMany(cascade = CascadeType.PERSIST)
    public Set<Tag>      tags;

    @OneToMany(mappedBy = "post", cascade = CascadeType.ALL)
    public List<Comment> comments;
    
    public Post(User author, String title, String content) {
        this.comments = new ArrayList<Comment>();
        this.tags = new TreeSet<Tag>();
        this.author = author;
        this.title = title;
        this.content = content;
        this.postedAt = new Date();
    }
    
    public Post addComment(String author, String content) {
        Comment newComment = new Comment(this, author, content).save();
        this.comments.add(newComment);
        this.save();
        return this;
    }
    public Post previous() {
        return Post.find("postedAt < ? order by postedAt desc", postedAt).first();
    }

    public Post next() {
        return Post.find("postedAt > ? order by postedAt asc", postedAt).first();
    }
   
    public Post tagItWith(String name) {
        tags.add(Tag.findOrCreateByName(name));
        return this;
    }
    
    public static List<Post> findTaggedWith(String tag) {
        return Post.find("select distinct p from Post p join p.tags as t where t.name = ?", tag)
            .fetch();
    }
    
    public static List<Post> findTaggedWith(String... tags) {
        return Post
            .find(
                "select distinct p from Post p join p.tags as t where t.name in (:tags) group by p.id, p.author, p.title, p.content,p.postedAt having count(t.id) = :size")
            .bind("tags", tags).bind("size", tags.length).fetch();
    }
 
}
